What a mess. The temp server was not configured to run as a main server and, since it had no keyboard, it'd just sit there and wait for someone to allow it to boot if it rebooted itself... Which it seemed to do when the CPU fan, already caked with dust and ineffective, ate itself and started spinning at about 10% speed.
So... Currently still running on the temp server. The new server will be installed later today, as soon as I find a new power supply for it.
Extra thanks to HP for putting 2 nonstandard supports in the case. I had to beat the shit out of it with a hammer to get my new mobo installed! =)
Then it's migration time. Apparently moving the database from MySQL4 to MySQL5 isn't as simple as copying the DB files. =/